The invention relates to a device for connecting a window lifter arm to a movable window pane of a motor vehicle.
DE 31 08 244 A1 describes a snap-fitting connecting device between a window pane of a motor vehicle and a window pane lifter. The window pane lifter consists of two interconnected channel-like profiled sections of which one encloses an area of the lower edge of the pane and is fixed to same. The other downwardly open profiled section supports at its ends inwardly aligned hooks which can enter into engagement with projections of angled elements of the lifter device whereby a keyed connection can be produced. The connecting elements are snapped in forcefully by moving the window pane against the upper stop position whereby at the same time, the window pane is automatically aligned in the frame structure and additional manual adjustments are not necessary during fitting.
Since however the profile-like coupling element has to be pre-fitted on the lower edge of the pane, the thicker structure resulting therefrom normally leads to difficult insertion of the window pane into the door shaft. As a result of the necessarily missing seal in this area to accommodate the thicker structure of the pane, during fitting, there is always the risk of damage to the paintwork. A further problem is in the small tolerances which are required in the snap-in area of the coupling element in order to avoid operating noises when moving the window lifter.
A variation which is very similar to that described above and having similar disadvantages is known from the JP A 6-135228. The elements fixed on the lower edge of the window pane have at their free ends conical abutment-like areas associated with the U-profiled connecting elements of the window lifter. They also have inclined guides with which the conical areas of the elements fixed on the window pane can enter into engagement. When bringing the connecting elements together, the arms of the U-profiled sections are elastically spread out. At the end of the fitting process, inwardly aligned hooks provided at the free ends of the U profiled sections engage over the projections of the conical abutment-like areas of the other elements. However there is the drawback that the part of the connecting element fixed on the window pane and angled away from the edge of the pane shortens the lift which can theoretically be carried out.
From DE 29 23 039 C2 a lift rail is known which is fixed by adhesive in the area of the lower edge of the window pane whereby the sliders of the lever arms of a cross-arm window lifter are displaceable guided in the lower part of the lift rail designed as a C section. The connection between the window lifter and the window pane is produced by screw connections. Also, the fitting of this lifter rail is provided outside of the door.
U.S. Pat. No 4,866,895 describes a connecting device with a one-piece plastics part which can be attached in the area of the lower edge of the pane and clips in through a hole in the pane. This plastics part has on both sides resilient wings associated with recesses in the lifter rail in which the wings engage at the end of assembly. The drawback with this solution is in the comparatively weak load-bearing ability of the connecting device since the plastics is inclined to flow at high temperatures and can thus only transfer weak draw forces.
The connecting device known from JP A 6 221052 is likewise a plastics part which can be fixed by clipping into a hole in the lower edge of the pane. Fixing the lifter rail is carried out by a screw which is screwed through the plastics part and through the hole in the pane. This solution has the drawback that adjusting the window pane is riot possible during its assembly through the connecting elements.